Reversible non-woven needled fabrics and methods of making them



A iil i i, 1970 D. W. CROSBY REVERSIBLE NON-WOVEN NEEDLED FABRICS ANDMETHODS OF MAKING THEM Filed March 16 1966 WTHHHHHIIH United StatesPatent 3,506,530 REVERSIBLE NON-WOVEN NEEDLED FABRICS AND METHODS OFMAKING David Winston Crosby, Pontypool, England, assignor to [CI FibresLimited, Pontypool, England, a corporation of Great Britain Filed Mar.16, 1966, Ser. No. 534,838 Claims priority, application Great Britain,Apr. 3, 1965, 14,233/65 Int. Cl. D04h 11/08 US. Cl. 161-67 11 ClaimsABSTRACT OF THE DISCLOSURE A reversible nonwoven fabric is made by.interposing a fibrous interlay between two pre-bonded fibrous webs,needling through one fibrous web to orient some of the interlay fibresthrough the opposite web in the form of tufts without appreciableorientation of the fibres in said web, repeating the needling from theother side of the three-layer structure, and then bonding the fibres ofthe interlay.

DISCLOSURE This invention relates to nonwoven fabrics and to methods ofmaking them and is particularly concerned with reversible nonwovenfabrics and to methods of making them involving, as an essentialoperation, the needlepunching of a composite fibrous structure.

According to this invention, in one of its aspects, there is provided areversible nonwoven fabric which comprises a fibrous interlay interposedbetween two layers each constituted by a fibrous web wherein fibres arebonded together, with some fibres from the fibrous interlay orientedthrough a bonded fibrous web layer as fibre tufts and other fibres fromthe interlay oriented through the other bonded fibrous web layer asfibre tufts, said fibre tufts being set in position as a result of thebonding together of fibres in the fibrous interlay.

The constituent fibres of the fibre tufts may be substantially straightor they may be crimped. When the fibre tufts contain crimped fibres itis generally the case that fibres present in the fibrous interlay arealso crimped. The presence, in the fibre tufts, of crimped fibres isassociated with advantages, for instance, more effective coverage of theunderlying layers, and a superior resilience, compared with fibre tuftscontaining straight or substantially uncrimped fibres.

Preferably, the fibres present in the fibre tufts and which extendoutwardly from the fibrous interlay, are oriented in planes normal orsubstantially so to the planar surfaces of the fabric.

The fibres oriented through the bonded fibrous web layers project beyondthe planar surfaces of the layers as fibre tufts, and provided thesetufts are well-defined, especially in relation to the length theyproject beyond the underlying layer, and sufiiciently numerous, theyform a definite layer of fibre tufts contiguous with the planar surfaceof each of the bonded fibrous web layers. In some instances the fibretufts may lack the necessary definition, or be too few in number toprovide a definite layer. It is possible to arrange that the fibre tuftson one surface of a fabric actually constitute that surface by forming adefinite layer, while in the opposite surface the' fibre tufts do notform a layer, and the surface is constituted both by fibre tufts and theunderlying bonded fibrous web.

The arrangement of fibrous from the fibrous interlay through the twofibrous web layers not only makes for a reversible nonwoven fabric, butfurther provides for the integration of the fibrous interlay with thetwo outer layers between which it is sandwiched, so that the fabricexhibits an adequate dimensional stability and resistance todelamination.

The invention further includes in another of its aspects a method ofmaking reversible nonwoven fabrics which comprises interposing a fibrousinterlay between two bonded fibrous webs to form a composite structure,subjecting the composite structure to a needle-punching operation,wherein the needles enter from one surface of the composite structureand orient fibres in the fibrous interlay through a bonded fibrous web,and then to a further needle-punching operation wherein the needlesenter from the opposite surface of the composite structure and fibres inthe fibrous interlay are oriented through the other bonded fibrous weband then treating the needlepunched product to bond together fibres inthe fibrous interlay.

When the fibrous interlay consists of, or contains a substantialproportion of fibres which possess a latent crimp, the development ofthis crimp provides a fabric with advantageous properties. The crimpdevelopment may be accomplished in the same treatment to which theneedlepunched product is subjected for the purpose of bonding togetherfibres in the fibrous interlay, or in a separate treatment prior orsubsequently thereto.

The expression bonded fibrous web as used herein means an assembly ofrelatively loosely associated fibres, which has been subjected to one ormore treatments, to bond together fibres in an assembly therebystrengthening and stabilising it. The bonding together of fibres may,for instance, be based on the entanglement of contiguous fibresresulting from the needlepunching of the fibrous assembly, or on theadhesive union between fibres.

In one suitable treatment a bonding agent is incorporated in theassembly during its fabrication, or introduced into it so thatindividual fibres therein, through the agency of the bonding agent, aresecured one to another. A treatment of the latter kind may be combinedwith a needle-punching operation in a conventional needle loom so thatfibres in the fibrous Web are bonded both mechanically and by means of abonding agent.

In the needle-punching operation to which the composite structure, ofwhich the bonded fibrous webs are part, is subjected, it is necessarythat the bonded fibrous webs should permit the barb needles to passtherethrough without extensive disruption or reorientation ofconstituent fibres which would result if the barbs in the needlesengaged fibres which lay in the path thereof. With this in mind, it maybe advantageous to utilise as the bonded fibrous web structures in whichthe fibres undergo, on contact with the needles, local displacement ordeformation Whilst resisting disruption or gross displacement.

Bonded fibrous webs in which at least some of the individual fibrespossess a three-dimensional crimped configuration are found to beparticularly convenient, especially if the bonding agent, if such atreatment be used to confer stability on the fibrous web, be confined todiscrete areas throughout the Web. Snob webs possess a relatively open,stereoreticulate structure with a multiplicity of intercommunicatingvoids which facilitate the uninterrupted passage through the web of theneedles during the needlepunching operation. The fibrous webs describedin application, Ser. No. 342,300, now abandoned, provide particularlyconvenient bonded fibrous webs for use in this invention, for the fibresin such webs are heterofilaments, that is to say, they contain two ormore components arranged in an adherent relationship along the length ofthe fibre and, as a result, possess a latent crimp, as well as abuilt-in binding action, the latter attributable to the presence in thefibres of a potentially adhesive component.

On activation, the potentially adhesive component serves as a bondingagent to secure together fibres in the web but, it does not readilymigrate from its position in the fibre, so that even after activation itremains localised and does not spread throughout the web in the manner,for example, of an adhesive introduced into the web by its passagethrough a bath of the adhesive. The restriction of the bonding agent torefined spot bonds is found to facilitate the needle-punching operation.

For more detailed information relating to the nature of theheterofilaments, their formation into a fibrous web and the bonding,and/or crimping of fibres therein reference should be made to thespecification accompanying the aforementioned application.

The two bonded fibrous webs which constitutes the outer layers of thecomposite structure may have the same fibre composition or they may havea different fibre composition, and in both instances they may be bondedin a like or different manner.

The thickness of the bonded fibrous web has to be considered in relationto the length of the fibres in the fibrous interlay, and the depth ofneedle-punching employed, for it is an essential feature of thisinvention that fibres should extend from the fibrous interlay through abonded fibrous web layer, at least to the surface thereof. Preferably,the bonded fibrous webs have a thickness i.e. the dimension between thesurface in contact with the fibrous interlay and the outer surface ofthe web, which does not exceed half the average length of fibres(assumed to be staple) in the fibrous interlay.

The fibrous interlay may comprise any loose assemblage of natural orsynthetic fibres and it may be obtained, for example, by carding orgarnetting process, by air-deposition or by fiuid paper-makingtechniques. The fibrous interlay may vary considerably in thicknessalthough it should be borne in mind that it must have thickness adequateto provide fibres for reorientation in two directions and fibre tuftformation. Again, the length of fibres within the fibrous interlay mustbe such that on reorienta tion they are capable of passing through thebonded fibrous web layers and, where appropriate, to project beyond it,the desired amount.

In most instances, it is preferred to use fibres having a length inexcess of two inches. Continuous filamentary structures, for example,those prepared by forwarding freshly extruded continuous filaments bymeans of an aspirator jet onto a stationary or travelling surface, forexample, a conveyor belt, may also be used as the fibrous interlay.

The fibrous interlay may have a similar fibre composition to one or bothof the two bonded fibrous webs as the outer strata of the compositestructure, or it may have a composition different from both those bondedfibrous webs. Interesting and useful effects can be obtained byconstituting the fibrous interlay of fibres having different dye uptakecharacteristics from the bonded fibrous webs. In those instances whereit is desired to have crimped fibres present in the fibre tufts, thefibrous interlay should contain crimped fibres or fibres with a latentcrimp amenable to development, subsequently to the needle-punchingoperation, by an appropriate treatment.

A variety of filaments can be made in such a manner that they possess alatent crimp.

One type of filament which possesses latent crimp and which affordsparticularly useful reversible fabrics according to this invention is aheterofilament, that is to say, a unitary filament comprising two ormore components arranged continuously along the length of the filament,and in which the latent crimp is a reflection of the different physicalproperties, for example, different shrinkage behaviour, possessed by thecomponents of the heterofilaments. Among suitable heterofilaments,mention may be made of these based on the polyamide system, for example,a poly(hexamethylene adipamide)/poly(epsilon caprolactam) orpoly/(hexamethylene adipamide)/poly (hexamethyleneadipamide)-poly(epsilon caprolactam) copolymer heterofilament,polyesteramide, polyester, polyurethanes, polyolefin, polyacrylonitrile,and the polyvinylidene system. The components of the heterofilament maybe arranged, for example, in an eccentric sheath and core or in'aside-by-side relationship.

Another type of fibre possessing a latent crimp is de rived from edgecrimped yarns, for example, poly(hexamethylene adipamide) orpoly(ethylene terephthalate) edge-crimped yarns, available commerciallyunder the registered trade name Agilon, which have been heated undertension so as temporarily to remove the crimp. The crimp in these fibresmay be restored by heating them in a relaxed condition, at a temperaturein excess of that at which the crimp was temporarily removed.

Fibres derived from yarns which have been subjected to a gear crimpingoperation may also possess a latent crimp which can be developed by asuitable treatment.

The treatment by which fibres in the fibrous interlay are bondedtogether may take a variety of forms.

For example, the fibrous interlay may contain a thermoplastic resin inpowder form with a softening point lower than that of fibres present inthe needled structure and the bonding of fibres in the fibrous interlaymay be accomplished by heating the needled structure to a temperaturesufficient to melt the powdered resin but not sensibly to affect thefibres. Instead of being present in powder form, the thermoplasticmaterial may be incorporated in the fibrous interlay in the form of asheet which, in the needling operation, is disrupted by the needles andto a certain extent at least distributed throughout the interlay.

When the fibrous interlay consists of, or contains heterofilaments ofthe kind previously mentioned, the bonding of fibres therein canconveniently be achieved by the activation, most commonly by heat,although a chemical medium may be suitable in some instances, of thepotentially adhesive component thereof. Consequently, the utilisation inthe fibrous interlay of fibres of this type obviates the necessity ofproviding the fibrous interlay with an extraneous bonding agent.Furthermore, on account of their construction, heterofilaments possess alatent crimp, the development of which is generally attained by anappropriate heat treatment, which may in suitable instances be the sameheat treatment by which fibre bonding is effected. The development ofcrim is reflected in a bulking of the fibrous interlay so that thestructure has an increased resilience and, in the deformation of thefibre tufts which adopt convoluted configurations and spread out in theplane of the fabric thereby providing, in those fabrics in which thefibre tufts are arranged in distinct strata, for enhanced coverage ofthe underlying fibrous web layer.

However achieved, the bonding of fibres in the fibrous interlaystabilises that layer and, through adhesive union, more effectively keysthe fibre tufts in position which consequently (relative to comparablefabrics in which fibres in the fibrous interlay are not bonded together)are of improved definition and have a superior resistance to extraction,for example, when the fabric is vacuumcleaned.

The invention is further described in the following illustrative exampleand the accompanying drawings wherein:

FIGURE 1 is a diagrammatic view sequentially illustrating an embodimentof the method of this invention and showing the apparatus assemblyemployed;

FIGURE 2 is a cross-sectional view, somewhat diagrammatic, of theneedle-punched product which is obtained by needle-punching fibres fromthe fibrous interlay through the two bonded fibrous web layers using theapparatus assembly shown in FIGURE 1; and

nonwoven fabric according to this invention, resulting from the methoddescribed with reference to FIGURE 1, and using the apparatus assemblyshown therein.

Referring to the drawings, and more particularly to FIGURE 1 thereof,reference numeral has been applied to indicate a supply roll of a bondedfibrous web which is unwound therefrom and moved, in the horizontalplane, from left to right, as a layer 11 upon the surface of atravelling conveyor belt 12. A fibrous web .13 which, in this instance,contains asubstantial proportion of staple fibres derived fromheterofilaments having a latent crimp and a heat-activatable potentiallyadhesive component, is withdrawn from a supply roll 14 and continuouslysuperimposed upon the layer 11 and moved at the same rate and in thesame direction as that layer. There is a loose physical engagementbetween the two layers. Reference numeral 15 indicates another supplyroll of a bonded fibrous web, which may be the same as the bondedfibrous web from supply roll 10, or it may be a different bonded fibrousweb, This bonded fibrous web is deposited as a layer 16 upon thestructure comprising fibrous web 13 and layer 11., The compositestructure 17, in which the fibrous web 13 constitutes a fibrous interlaybetween the two bonded fibrous webs 11 and 16, is then fed to a singlebed needle loom of conventional design, generally indicated by referencenumber 18. Needle loom 18 comprises a horizontal surface 19 supportingthe composite structure, and a needle-board 20 adapted for reciprocationin the vertical plane, and containing conventional barb needles 31 whichpass in and out of the composite structure 17.

The movement of the needles in and out of the composite structure isachieved without any marked occurrence of broken or reoriented fibres inbonded fibrous webs as layers 11 and 16 but, in passage through thefibrous interlay 13, the barbs in the needles pick up fibres therein andpush them downwardly into the bottom layer 11. The depth ofneedle-punching, and the length of fibre in the fibrous interlay are soarranged that those reoriented fibres are carried by the needles,through the bottom layer, so that part of the reoriented fibres projectbeyond the surface of that layer as fibre tufts, generally indicated byreference numeral 21.

The composite structure on emergence from the needle loom 18 is carriedaround a roller 22 and then through a second needle loom 23. The variousparts, and mode of operation of this needle-loom are similar to thefirst needle-loom but, in the needle-punching operation conducted inthis needle-loom, the needles penetrate the oppositesurface of thecomposite structure to that in the first needle-punching operation andconsequently, fibres are carried, by the needles, from the fibrousinterlay 13 through the layer 16 which is now the bottom layer of thestructure and fibretufts project beyond the surface of that layer.

' The fibrous web 13 as the fibrous interlay, instead of being deliveredfrom the supply roll 12 can be deposited uponthe bonded fibrous Weblayer 11 from a garnetting, carding or air-laying machine, or indeedfrom any suitable means for depositing a relatively loose assemblage offibres.

Instead of utilising two separate needle looms to effect the first andsecond needling operations, the composite structure, after the firstneedle-punching operation, may be inverted so that the layer 11 nowconstitutes the top layer of the composite structure which in thatconfiguration is passed once again through the same needle loom. It isalso possible to effect two needle-punching operations, involving theinitial penetration of needles into opposite surfaces of the compositestructure, in a single pass through a double-bed needle loom.

FIGURE 2 illustrates the product obtained after the composite structurehas been subjected to needle-punching in opposite directions relative tothe disposition of the discrete layers of the composite structure.

As shown, the two layers 11 and 16 of bonded fibrous webs have retainedtheir configuration and there are few broken fibres, and minimalreorientations thereof, as a result of the passage of needlestherethrough. However, fibres of the fibrous interlay 13 have beenreoriented as a consequence of the needle-punching. The direction of thereorientation is dependent upon the direction of the needle-punching bywhich it was effected.

Thus, in the needle-punching operation wherein needles initiallypenetrated layer 16, those fibres, in the fibrous interlay 13, whichwere engaged by the needle barbs and carried through the opposite layer11, were reoriented into vertical planes. Those vertically disposedfibres comprise a part 25 embedded within the bonded fibrous web aslayer 11 and a part which projects beyond the surface 26 of layer 11 asa fibre tuft 27. The part 25 embedded within the layer 11 may be likenedboth structurally and functionally to the roots of the tree and servesto anchor each of the fibre tufts in position. The fibre tufts ineffect, form a new outermost surface which serves to hide layer 11 fromvisual discernment. Needle-punching in the reverse direction, that is tosay, when the needles initially penetrated the surface of layer 11,reorients fibres from the fibrous interlay through layer 16 and theresulting vertically disposed fibres comprise a part 28 embedded withinthe layer 16 and a part which projects beyond the surface 29 of thelayer 16 as a fibre tuft 30. In consequence of the needle-punching inthe two directions, opposite surfaces of the product are constituted byfibre tufts so that the two surfaces have a similar appearance.

The needle-punched product 33 with fibre tufts present on both surfaces,is then passed through an oven 34, wherein it is exposed to atemperature which is so selected and controlled that it effects, withoutsensibly affecting fibres in the two bonded web fibrous layers;

(i) the development of crimp in fibres present in the fibrous interlayand fibre tufts; and

(ii) the activation of the.potentially adhesive component present in theheterofilament fibres.

The fabric derived from the combined needle-punching and heattreatments, and which is wound-up on product reel 35 is illustrated in across-sectional view in FIG- URE 3.

As a result of the crimp development the fibre tufts 27 and 30 haveeffloresced and spread out in the plane of the fabric to formmushroom-shaped structures 31 and 32. The efilorescence of the fibretufts and the associated transformation into mushroom-shaped structuresis refiected in an enhanced coverage of the underlying surface of thebonded fibrous web layers 11 and 16, and an improved resilience, whichis reflected in an enhanced resistance of the fibre tufts constitutingthe pilous surface to deformation, arising say from the application of aload thereto. Moreover, the fabric containing such tufts has a superioraesthetic appeal and a softer, more attractive handle'compared withsimilar fabrics in which the tufts are straight, or substantiallyuncrimped.

Either surface of the fabric can be used as the functional surface inthose applications which call for a piloussurface material. Quite apartfrom their role in providing the fabric with surfaces comprising fibretufts, the reoriented fibres interlock the fibrous interlay to the twoouter layers thereby providing an integrated needled fabric having adegree of dimensional stability and a resistance to delamination.

The adhesive union between the fibre tuft roots located in the fibrousinterlay and the heterofilament fibres present in the interlay keys thefibre tufts in position and needle-punching density, and consequentlycan readily be varied. When there are insuflicient fibre tufts, or if,because of the low depth of needle-punching, they project only a veryshort distance beyond the underlying bonded fibrous web, they may notform a definite layer but rather part of the surface of the bondedfibrous web.

The bonding of fibres in the fibrous interlay may be accomplished bymeans other than through the heat activation of a potentially adhesivecomponent of heterofilament fibres, these other means, which include theactivation of a thermoplastic resin present in the interlay in the form,for example, of a powder or a film, are useful in the absence, from thefibrous interlay, of suitable heterofilament fibres.

EXAMPLE A quantity of 6 denier, three inch staple fibres formed fromheterofilaments comprising equal proportions by weight ofpoly(hexamethylene adipamide) as one component and an 80/20 randomcopolymer of poly(hexamethylene adipamide)-poly(epsilon caprolactam) asthe other component, the two components being arranged in a side-by-siderelationship, was laid into a random or isotropic fibrous web leaving aweight of approximately 3 ounces per square yard by means of a Proctorand Schwarz Duoform air-laying machine. The web was then passed througha single bed needle loom supplied by William Bywaters Limited of Leeds,equipped with 36 gauge regular barb needles. The needle penetration wasadjusted to penetrate /2 inch and the rate of needling Was controlled toeffect 200 punches per square inch. As a result of this needlingoperation fibres in the fibrous web were bonded together through thefibre entanglement and associated frictional forces. Fibre bonding wasfurther developed by passage of the needled fibrous web through an Efcoconveyorised oven operating at a throughput of ten feet per minute and atemperature of approximately 230 C. The effect of this heat treatmentwas two-fold; in the first place, it resulted in the development offibre crimp, and secondly it activated the copolymer component, as thepotentially adhesive component of the heterofilaments, which becameadhesive and, in that condition, bonded contiguous fibres together. Theresulting bonded fibrous web had a relatively bulky stereoreticulatestructure containing a multiplicity of intercommunicating voids.

Another bonded fibrous web was made in a manner identical to thatpreviously described.

The two bonded fibrous webs, each inch thick, were brought together withan interleaving carded layer, half an inch thick, of 6 denier, threeinch, heterofilament staple fibres comprising equal proportions byweight of poly(hexamethylene adipamide) as one component and an 80/ 20random copolymer of poly(hexamethylene adipamide) and poly(epsiloncaprolactam) as the other component, the two components being arrangedin a side-by-side relationship, having a weight of 5 to 6 ounces persquare yard, on a traveling belt and using the method described withreference to FIGURE 1 of the accompanying drawings.

The composite structure so formed was passed once through the single bedneedle loom equipped with 36 gauge regular barb needles, the speed ofthe structure through the loom being adjusted to effect 250 punches persquare inch and the needle penetration adjusted to pentrate a shortdistance through the bottom bonded fibrous web layer whereby the firstfew barbs of each needle passed therethrough. The needles passed throughboth of the outer strata without any excessive breaking of fibres in thebonded fibrous webs which constituted these layers, but the barbs on theneedles caught fibres in the fibrous interlay and dragged them throughthe bottom bonded fibrous web. As a result, fibres from the interlaywere reoriented into planes normal to the planar 8. surfaces of thecomposite structure. A length (approximately inch) of each of thereoriented fibres projected beyond the surface of the bottom layer aspart of a fibre tuft (each of which was composed of many fibre ends),and all the fibre tufts provided the structure with a new surface whichhad the appearance of a conventional pilous surface. The structure wasthen inverted and passed once again through the same needle loomequipped with identical needles and adjusted to effect the same needlingdensity and needle penetration.

In this pass through the loom, the needles entered the structure fromthe surface of fibre tufts resulting from the first needle-punching (andbetween the actual tufts) so that the direction of needle-punching withreference to the arrangement of layers making up the compositestructure, was the opposite of the direction in the previousneedle-punching operations. The needles entered the structure betweenthe fibre tufts without any significant destruction of the tufts, andthey reoriented fibres from the fibrous interlay through the otherbonded fibrous web, beyond the surface of which fibre tufts projected.

The two opposite surfaces of the needle-punched product were composed offibre tufts, standing proud above v an underlying bonded fibrous web,and they had a similar appearance, simulating the surfaces of aconventional pilous surface material.

The needle-punched product was then passed on a conveyor belt through anair oven operating at a throughput of ten feet per minute and atemperature of approximately 240 C. The effect of this heat treatmentwas two-fold. In the first place, it developed potential crimp in theheterofilament fibres in the fibrous interlay and those of the fibretufts. As a consequence of the development of crimp, the fibre tuftsunderwent an efflorescence,

and spread-out in the plane of the fabric to form mush room-shapedstructures, and a bulking effect was manifest in the fibrous interlayitself. Secondly, it activated the copolymer component of theheterofilaments throughout the structure and so bonded together fibresin the fibrous interlay. The bonding of fibres in the fibrous interlayprovided for the enhanced anchorage of the fibre tufts,

as did the coalescence between the part of each of the fibre tuft rootsand heterofilament fibres in the bonded cellent permanence of form. Theywere much more securely held in position than fibre tufts in a similarfabric in which fibres in the fibrous interlay were not bonded together.

What I claim is:

1. A reversible nonwoven fabric which comprises a nonwoven .fibrousinterlay interposed between two layers each constituted by a nonwovenfibrous web wherein fibres are bonded together, with some fibres fromthe fibrous interlay oriented through a bonded fibrous web layer asfibre tufts and other fibres from the interlay oriented through theother bonded fibrous web layer as fibre tufts, said fibre tufts beingset in position as a result of the bonding together of fibres in thefibrous interlay, and said tufts consisting essentially of fibres fromsaid fibrous interlay.

2. A reversible nonwoven fabric as claimed in claim 1 wherein the fibretufts contain crimped fibres.

3. A reversible nonwoven fabric as claimed in claim 1 whereinconstituent fibres of the fibre tufts are heterofilaments.

4. A reversible nonwoven fabric as claimed in claim 1 wherein the fibretufts on one or both of two opposite surfaces of the fabric constitute adefinite layer contiguous with the planar surface of the underlyingbonded fibrous web layer.

5. A reversible nonwoven fabric as claimed in claim 1 wherein the fibretufts on at least one of two opposite surfaces of the fabric do notconstitute a definite layer so that the surface is constituted both byfibre tufts and the bonded fibrous web layer.

6. A reversible nonwoven fabric as claimed in claim 1 wherein the bondedfibrous web contains fibres which are adhesively united.

7. A reversible nonwoven fabric as claimed in claim 6 wherein the bondedfibrous web contains crimped fibres.

8. A method of making reversible nonwoven fabrics which compriseinterposing a nonwoven fibrous interlay between two pre-bonded nonwovenfibrous webs to form a composite structure, subjecting the compositestructure to a needle-punching operation, wherein the needles enter fromone surface of the composite structure and orient fibres in the fibrousinterlay through a bonded fibrous web without any appreciableorientation of the fibres of the fibrous web, and then to a furtherneedle-punching operation wherein the needles enter from the oppositesurface of the composite structure, and fibres in the fibrous interlayare oriented through the other bonded fibrous web without anyappreciable orientation of the fibres of said other fibrous web, andthen treating the needlepunched product to bond together fibres in thefibrous interlay.

9. A method of making reversible nonwoven fabrics as claimed in claim 8wherein the fibrous interlay contains a substantial proportion of fibreswhich possess a latent crimp, which is developed in the same treatmentas References Cited UNITED STATES PATENTS 1,722,764 7/1929 Rasch 161-803,122,140 2/1964 Crowe 156-148 XR 3,122,142 2/1964 Crowe 156-148 XR3,347,736 10/1967 Sissons 161-67 3,383,273 5/1968 Pearson et a1. 161-81XR ROBERT F. BURNETT, Primary Examiner 20 R. H. CRISS, AssistantExaminer US. Cl. X.R.

